Add static method WebApkIconHasher::DownloadAndComputeMurmur2Hash

chrome/browser/android/webapk/webapk_icon_hasher.h

Index: chrome/browser/android/webapk/webapk_icon_hasher.h
diff --git a/chrome/browser/android/webapk/webapk_icon_hasher.h b/chrome/browser/android/webapk/webapk_icon_hasher.h
index 4a337106990f5d977c70017b18143d053a1906c2..ff54b97738a5bb4dd1ec64c5dc1203fe00d2e1b2 100644
--- a/chrome/browser/android/webapk/webapk_icon_hasher.h
+++ b/chrome/browser/android/webapk/webapk_icon_hasher.h
@@ -25,30 +25,31 @@ class WebApkIconHasher : public net::URLFetcherDelegate {
   using Murmur2HashCallback =
       base::Callback<void(const std::string& /* icon_murmur2_hash */)>;
 
+  // Creates a self-owned WebApkIconHasher instance. The instance downloads
+  // |icon_url| and calls |callback| with the Murmur2 hash of the downloaded
+  // image. The hash is taken over the raw image bytes (no image
+  // encoding/decoding beforehand). |callback| is called with an empty string if
+  // the image cannot not be downloaded in time (e.g. 404 HTTP error code).
+  static void DownloadAndComputeMurmur2Hash(
+      net::URLRequestContextGetter* request_context_getter,
+      const GURL& icon_url,
+      const Murmur2HashCallback& callback);
+
+ private:
   WebApkIconHasher(
       net::URLRequestContextGetter* request_context_getter,
       const GURL& icon_url,
       const Murmur2HashCallback& callback);
   ~WebApkIconHasher() override;
 
-  // Downloads |icon_url_|. Calls |callback_| with the Murmur2 hash of the
-  // downloaded image. The hash is taken over the raw image bytes (no image
-  // encoding/decoding beforehand). |callback_| is called with an empty string
-  // if the image cannot not be downloaded in time (e.g. 404 HTTP error code).
-  void DownloadAndComputeMurmur2Hash();
-
- private:
   // net::URLFetcherDelegate:
   void OnURLFetchComplete(const net::URLFetcher* source) override;
 
   // Called if downloading the icon takes too long.
   void OnDownloadTimedOut();
 
-  // For retrieving URLRequestContext. Owned by the caller of this class.
-  net::URLRequestContextGetter* url_request_context_getter_;
-
-  // The icon URL.
-  GURL icon_url_;
+  // Calls |callback_| with |icon_murmur2_hash|. Also deletes the instance.
+  void RunCallback(const std::string& icon_murmur2_hash);
 
   // Called with the image hash.
   Murmur2HashCallback callback_;